You have three different signal levels to consider here:
- Eurorack level (VERY HIGH!)
- Pro line level (+4dBu)
- Consumer line level (-10dBV)
Your amp is made to receive #3. The TRS jacks on the Palette, as ScottMFR wrote, don’t do anything without a module connected to them. I believe the Stereo Line Out 1U module reduces the Eurorack level signals and sends #2, which is hotter than #3, but it can work - I’ve been sending +4dBu to my old Adcom amp and Mirage speakers/sub for years, and nothing bad has ever happened. NAD makes great stuff, and I’d be surprised if your amp couldn’t handle +4dBu (but of course I assume no liability). But yeah, be careful with volume…but it isn’t just a matter of keeping the volume on your amp low. You should also turn down the volume/gain on the Stereo Line Out 1U to lower the signal being sent to your stereo.
Do not send Eurorack level signals to your amp!